docs: def search_for_oath_code(hsm, key_handle, nonce, aead, user_code, interval=30,
                           tolerance=0):
      """
      Try to validate an OATH TOTP OTP generated by a token whose secret key is
      available to the YubiHSM through the AEAD.
  
      The parameter `aead' is either a string, or an instance of YHSM_GeneratedAEAD.
  
      Returns timecounter value on successful auth, and None otherwise.
      """
  
      # timecounter is the lowest acceptable value based on tolerance
      timecounter = timecode(datetime.datetime.now(), interval) - tolerance
  
      return search_hotp(
          hsm, key_handle, nonce, aead, timecounter, user_code, 1 + 2*tolerance)